package JavaIO;

import java.io.*;
import java.util.*;

public class Main {
    public static PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));

    public static void main(String[] args) {
        System.out.println("Hello world!");
    }
}

//快速读入
class Read {
    //字符串裁剪
    StringTokenizer st = new StringTokenizer("");

    BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));

    String next() throws IOException {
        while(!st.hasMoreTokens()) {
            st = new StringTokenizer(bf.readLine());
        }
        return st.nextToken();
    }

    String nextLine() throws IOException{
        return bf.readLine();
    }

    int nextInt() throws IOException {
        return Integer.parseInt(next());
    }

    long nextLong() throws IOException {
        return Long.parseLong(next());
    }

    double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }
}